Keshu

Definition

Enzymes are biological catalysts. They speed up chemical reactions inside living organisms without being used up. For example, digestive enzymes like amylase help break down starch into sugar quickly, which would otherwise take too long.

Function

The main function of enzymes is to lower the activation energy of reactions. This means reactions can happen faster and at normal body temperature, instead of needing extreme heat or energy. That’s why life processes can occur smoothly in cells.

Active Site

Every enzyme has an active site, a special region where the substrate (the molecule it acts on) binds. The active site’s shape matches only its specific substrate, like a lock fitting a key, which is why enzymes are highly specific.

Nature

Most enzymes are proteins made from chains of amino acids folded into complex 3D structures. Their structure is very important for their function. A few exceptions exist, like ribozymes, which are made of RNA instead of protein.

Examples

• Amylase → breaks down starch into maltose (found in saliva & pancreas).

• Lipase → breaks down fats into fatty acids + glycerol (important in digestion).

• Protease (like pepsin, trypsin) → breaks down proteins into amino acids.

• Catalase → breaks hydrogen peroxide (toxic byproduct) into water + oxygen.

• DNA polymerase → helps in DNA replication by adding nucleotides.